Combination Therapy for Chronic Hepatitis C Infection

Background: \- GS-7977, GS-5885, GS-9669, and GS-9451 are new drugs for treating hepatitis C virus (HCV) infection. GS-7977 may help treat the infection when used with other treatments like interferon therapy. GS-5885, and GS-9669, and GS-9451 also lower the amount of HCV in the body. Researchers want to see whether GS-7977 can be combined with any of the other three drugs to treat HCV infection. Some participants will take GS-7977 and GS-5885. Others will take GS-7977, GS-5885 and GS-9669 or GS-7977, GS-5885 and GS-9451. Objectives: \- To see whether GS-7977 with GS-5885 alone or in combination with either GS-9669 or 9451 can be used to treat HCV infection. Eligibility: Individuals at least 18 years of age who have chronic HCV infection and have never been treated for it. Individuals at least 18 years of age who have chronic HCV infection and have not responded to interferon therapy. Individuals at least 18 years of age who have chronic HCV infection with advanced liver disease and have never been treated for HCV Design: Participants will be screened with a physical exam and medical history. Blood samples will be collected. A liver biopsy may also be performed. Some participants will take the two study drugs and some will take three study drugs. Those who take GS-7977 and GS-5885 will have one daily tablet named fixed dose combination or FDC. Those who take GS-7977 and CS-9669 will have three daily tablets taken once daily. Those who take GS-7977 and GS-5885 and GS-9451 will take 2 pills once a day. GS-7977 and GS-5885 will be combined in one pill and GS-9451 will be in another pill. Treatment will be monitored with frequent blood tests. These tests will check liver function and the level of HCV infection. Participants may have other blood tests as needed for treatment. Participants will have 4, 6 or 12 weeks of treatment depending on which study drugs are scheduled to take. After they complete their schedule, they will stop treatment with the study drugs. They may also have another liver biopsy. Participants will have regular follow-up visits over the next 48 weeks. They will have physical exams and provide blood samples....

Chronic hepatitis C virus (HCV) infection is a major public health problem with an estimated 180 million people infected worldwide. In the United States an estimated 4.1 million people are infected, and HCV is the principal cause of death from liver disease and leading indication for liver transplantation. While treatment with ribavirin (RBV) and pegylated interferon (PEG) in combination with boceprevir/telaprevir is the currently recommended therapy for chronic HCV infection and has superior cure rates compared to PEG+RBV alone in HCV monoinfected patients, treatment is still associated with a high incidence of adverse events (AEs), discontinuations, and poor cure rates in several populations. Recent studies have demonstrated that the use of a combination of antivirals, which target HCV without interferon (IFN), can cure HCV without additional toxicities. However, the determinants of response to IFN-free regimens have not been established. This is an open label study to assess the safety, tolerability, and efficacy of treatment with GS-7977 with GS-5885, alone or in combination with GS-9669 and/or GS-9451 (selective HCV nucleotide NS5B, NS5A, nonnucleotide NS5B and NS3 inhibitors, respectively) in HCV infected treatment naive and treatment experienced patients with early and advanced liver disease. The findings from this study will aid in our understanding of determinants of response to an IFN-free regimen in HCV infected patients for both patients with early and advanced liver disease as well as in patients who are treatment naive and those who have been treated before for HCV.